Introducer assembly and method for forming an introducer assembly

ABSTRACT

An introducer assembly includes a sheath having a sheath proximal end and distal end, and a passage therethrough. The introducer assembly further includes a handle assembly that is mechanically and/or bonded coupled with a tubular sheath.

RELATED APPLICATION

This application is a continuation-in-part of U.S. application Ser. No.11/537,919 filed Oct. 2, 2006, which is incorporated herein by referenceand made a part hereof.

TECHNICAL FIELD

Introducers and introducing assemblies, and more specifically anintroducer assembly including a bonded sheath assembly.

BACKGROUND

Introducer devices provide for access to the vascular system and areemployed for inserting medical devices such as catheters, guidewires,leads, infusion ports, dialysis ports, dialysis catheters, and others. Atypical procedure for gaining access to the central venous system or thearterial system with an introducer is the Seldinger Introduction Method.The Seldinger Method provides for insertion of a needle into thevasculature of a patient. Once the needle is in the vessel, thephysician aspirates the needle to assure that the needle is in thevessel, and to draw out air present in the bore of the needle. Thesyringe is removed and discarded. A guide wire is inserted through theneedle, and the needle is removed over the guide wire. The introducer,which includes a dilator and the sheath, is placed over the guidewireand inserted into the vessel. With the introducer and wire guide in thevessel, the dilator and wire guide are removed leaving only the sheathin the vessel. The desired medical device is implanted through thepassage of the sheath.

The sheath is optionally removed from the medical device. Some removablesheaths are formed of lubricious materials with low coefficients offriction, which is difficult to effectively couple or seal with othercomponents. Furthermore, the introducer device provides access to thevein or artery, and therefore control of bleeding and the intake of airis necessary, for example, through use of a valve.

Accordingly, what is needed is an introducer assembly which caneffectively seal against a wide variety of instruments withoutinhibiting the throughput of the instrument, or damaging the instrument.What is also needed is an introducer assembly which does not distract orinterfere with the implantation process.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a perspective view of an introducing assembly asconstructed in accordance with at least one embodiment;

FIG. 1B illustrates a cross-sectional view of a portion of anintroducing assembly as constructed in accordance with at least oneembodiment;

FIG. 2 illustrates side view of a portion of a sheath assembly asconstructed in accordance with at least one embodiment;

FIG. 3 illustrates side view of a portion of a sheath as constructed inaccordance with at least one embodiment.

FIG. 4 illustrates side view of a portion of a sheath as constructed inaccordance with at least one embodiment.

DESCRIPTION OF THE EMBODIMENTS

In the following detailed description, reference is made to theaccompanying drawings which form a part hereof, and in which is shown byway of illustration specific embodiments in which the invention may bepracticed. These embodiments are described in sufficient detail toenable those skilled in the art to practice the invention, and it is tobe understood that other embodiments may be utilized and that structuralchanges may be made without departing from the scope of the presentinvention. Therefore, the following detailed description is not to betaken in a limiting sense, and the scope of the present invention isdefined by the appended claims and their equivalents.

An introducer assembly 100 is illustrated in FIGS. 1A and 1B. Theintroducer assembly includes a sheath assembly 110 having a sheath 112with a passage 114 therethrough. The sheath 112 is coupled with a handleassembly 180 as further described below. The sheath 112 extends from asheath proximal end portion 116 to a sheath distal end portion 118, andis defined in part by a longitudinal axis. Near the sheath distal endportion 118 is a tapered portion, allowing for a more tapered transitionportion to taper to the dilator disposed therethrough.

The sheath 112 is formed of, in an example, fluorinated polymers suchas, but not limited to, PTFE (PolyTetraFluoroEthylene), FEP (FluorinatedEthylene-Propylene), or non-fluorinated polymers such as nylon,polyurethane, polyethylene, polyamide, polypropylene, or polyimide.These materials assist in provided lubricious surface proprieties. Thesheath material, such as the PTFE, is molecularly oriented in itsextruded state for optionally splitting the sheath. The molecularlyoriented sheaths do not necessarily require an additional mechanicalscoring operation to produce split lines. Instead, the orientedmolecules allow the sheath 112 to naturally peel like a banana.

In a further option, the sheath 112 includes various types of sheaths,for instance, the sheath 112 can comprise a sheath which has astrengthening material, such as a strengthening braid of material.Alternatively, the sheath 112 includes a sheath which is modified toassist in preventing bends and/or kinks along the sheath. In a furtheroption, the sheath 112 includes a co-extrusion of multiple units ordifferent types of materials. In yet a further option, the sheath 112includes a component having one or more coatings thereon. It should benoted the sheath 112 can be formed of combinations of one or more typesof the sheaths.

The introducer assembly 100 further includes an instrument such as adilator 120 that can be coupled with the sheath assembly 110, forexample, with a rotatable coupler 116. For example, the rotatablecoupler 116 includes a threaded portion that engages a projection orthread on the sheath assembly 110. The dilator 120 is removably disposedwithin a passage 114 of the sheath 112, and optionally is coaxial withthe sheath 112. The sheath 112 includes a support diameter which issized to receive a dilator 120 having a dilator diameter therethrough.It should be noted that other instruments such as leads and/orguidewires can be disposed through the sheath and sheath passage 114, aswill further be described below. The dilator 120 extends from a dilatordistal end to a dilator proximal end 124, where the dilator distal endis insertable into a patient, for example, over a needle or a guidewire.The dilator distal end optionally ends in a tapered end, allowing forease of transition within tissue of a patient. The dilator proximal end124 optionally includes features, such as a luer hub or threads, thatallows for other devices to be coupled thereto.

In one embodiment, the handle assembly 180 and the sheath 112 areremovable from around instruments disposed therein, such as a leaddisposed with the sheath 112. For example, the sheath 112 is removablefrom around the instrument without having to slide or otherwisemanipulate the introducer and/or the sheath over a proximal end of theinstrument. In one option, the handle assembly 180 and/or the sheath 112are removed from an outer perimeter along a cross-section of aninstrument disposed therethrough.

The sheath 112 and/or the handle assembly 180, for example, can beremoved from the instrument disposed therethrough in a number ofdifferent manners. For example, the sheath 112 can include structureintegral therewith or non-integral that allows for the sheath 112 to beseparated from around the instrument without damaging the instrument,and/or allows for the sheath 112 to be removed from the outer perimeterof the cross-section of the instrument. In some examples, the sheath 112is coupled with a handle assembly 180, and the handle assembly 180includes one or more tabs that are connected with the sheath 112 to tearthe sheath 112 off of the instrument. In another example, the structureincludes a tear strip, molecularly orientated material within thesheath, one or more openings in the sheath 112 allowing the sheath 112to separate at one or more locations that each can be used alone or incombination to separate the sheath 112 from around the instrument. Inanother option, the sheath 112 is at least partially dissolvable withina body, allowing the sheath 112 to be removed from the instrument. Inanother option, a slitting or splitting device such as a slitter can beused to removed the sheath 112, where the sheath 112 is removed byslitting. In yet another option, the sheath further includes one, two ormore tabs which can be used to separate the sheath away from theinstrument. Further options include a pre-weakened or scored sheath,allowing for the sheath to be manually removed by tearing, separating,or slitting, for example. In yet another example, the sheath includesmolecularly oriented material allowing for the sheath 112 to be removedfrom around the instrument.

The introducer assembly 100 optionally includes a valve 130 that issealingly associated with the passage 114 of the sheath 112, allowingfor substantial sealing of the passage 114. The valve 130 assists inpreventing fluids to exit from a patient when the sheath 112 is disposedwithin the patient. The valve 130 assists in preventing fluids fromexiting, yet permits passage of instruments through the valve 130, andin an option, substantially seals against the instruments that aredisposed therethrough.

The valve 130 is coupled with a portion of the introducer 110, forexample, within the handle assembly 180 of the introducer. The valve130, in an option, is removable from around an outer cross-sectionalperimeter of an instrument disposed through the introducer. For example,the valve 130 can include a mechanical weakening allowing for the valve130 to slide off to the side of the instrument. Alternatively, themechanical weakening can allow for the valve 130 to be torn or splitaway from the introducer. In yet another option, the valve 130 forms anadaptor that is attachable and removable by the user before, during, orafter an implant procedure. For example, the user can remove or attachthe valve assembly 130 with a fitting or other coupling.

As mentioned above, the handle assembly 180 is coupled to the sheath112, where they are coupled together at an interface 190. In an option,the interface 190 includes a proximal end portion 116 of the sheath 112and/or a portion of the handle assembly 180, such as in inner diameter184. In an option, the interface 190, such as the sheath proximal endportion 116 and/or the inner or outer diameter of the handle assembly180 includes a surface treated portion 186, such as textured portion186, for instance, as shown in FIG. 3. In an option, the texturedportion extends around at least a portion of an outer circumference ofthe sheath 112. In another option, the surface treated portion 186extends around the entire circumference of the sheath 112, at a proximalportion of the sheath 112.

The surface treated portion 186, such as the textured portion, is formedin an option by chemically etching, for example, the sheath proximal endportion 116. In an example, the sheath 112 is rinsed with a solution,such as alcohol. The sheath 112 and/or the handle assembly 180 arechemically etched with a solution such as, but not limited to sodiumnaphthalene/ethylene glycol dimethyl ether solution.

In another option, the surface treated portion 186 is formed by treatinga first portion 142 with a first treatment, for example, mechanicallytreating the first portion 142, as shown in FIG. 4, the sheath 112, ormedia blasting the sheath 112, such as the proximal portion of thesheath 112. For example, the sheath 112 can be blasted by one or moreof, alone or in combination, sodium bicarbonate (i.e. baking soda),sand, glass, mica, pumice, or dry ice (i.e. carbon dioxide). In yetanother option, the surface treated portion 186 is formed by sanding orgrinding the sheath 112, such as at a first portion 142 of the proximalportion of the sheath 112. In an option, the sanding or grinding of thesheath 112 is conducted with one or more of sand paper, grinding wheel,or a tooling stone.

Further options for forming the surface treated portion 186 or the firstportion 142 include, but are not limited to, treating the surfacetreated portion 186 with abrasives in a carrier liquid. For instance,the surface treated portion 186 can be treated with a slurry includingone or more of, alone or in combination, pumice, sand, mica, or glass.

In a further option, a second portion 144 of the interface is treatedwith a second treatment. The second treatment, such as a chemical etch,changes the surface characteristics of the sheath 112. For example, acontact angle of the sheath 112, measured with a goniometer, changesfrom a natural state (pre second treatment) of 80 degrees, to 70 degreesafter it has been chemically etched. The reduction in surface angleallows molten plastic to better bond with the sheath 112. In an option,the second portion 144 is chemically etched with a solution such as, butnot limited to sodium naphthalene/ethylene glycol dimethyl ethersolution. In an option, the second treatment is done after the firsttreatment. In an option, the second portion 144 overlaps at least aportion of the first portion 142.

In another option, the second portion 144 occupies the same area as thefirst portion 142.

In yet another option, the second treatment, such as the chemical etch,is partially or entirely removed from the sheath 112. For instance, atleast a portion 146 of the interface is treated with a third treatmentto remove the second treatment such as the chemical etch. In an option,the portion 146 is disposed at the proximal end of the sheath 112. In anoption, the third treatment includes mechanically treating the portion146, such as by buffing, blasting, or otherwise treating the portion146.

In still another option, the sheath 112 is masked prior to the secondtreatment, such as the chemical etch to control where the chemical etchoccurs. For example, the sheath 112 can be masked at 145 to preventchemical etch of the second treatment to occur at 145.

Referring again to FIGS. 1B, 2, and 3, the handle assembly 180 iscoupled to the sheath 112, in an example, by overmolding the handleassembly 180 over the sheath 112. In another option, the handle assembly180 can be preformed, and coupled with the sheath 112 by applying energyto the handle assembly 180 and/or the sheath 112, such as applying heat.During the process, the material of the handle assembly 180 bonds withthe sheath 112, and chemically bonds with the chemically etched portion.In a further option, one or more flow holes 119 are formed in the sheath112, such as by punching, prior to coupling the handle assembly 180thereto. The flow holes 119 allow for material of the handle assembly180 to flow therethrough, and further permit a mechanical bond of thehandle assembly 180 and the sheath 112.

Methods for forming the introducer assembly include the techniquesdiscussed above. Furthermore, methods include a method for forming theintroducer assembly includes forming a tube such as a fluorinatedpolymer tube, for example, by extruding the tube. The polymer tube formsa sheath extending from a sheath proximal end portion to a sheath distalend portion, and the sheath has a passage therethrough. The methodfurther includes surface treating the sheath 112 at a proximal end toform a handle interface.

Referring to FIG. 4, the method includes surface treating a portion,such as a first portion 142 of the sheath 112 with a first treatment. Inan option, the first treatment includes a mechanical treatment such asthe mechanical treatments discussed herein, including, but not limitedto media blasting the sheath 112 or texturizing the sheath 112. Inanother option, surface treating the interface portion or a firstportion 142 of the sheath with the first treatment includes treating thesheath with one or more of, alone or in combination, sodium bicarbonate,sand, glass, mica, pumice, and/or dry ice. In a further option, surfacetreating with the first treatment includes media blasting the sheathwith one or more of, alone or in combination, sodium bicarbonate, sand,glass, mica, pumice, and/or dry ice. In another option, surface treatingthe interface portion includes sanding and/or grinding the sheath. Inyet a further option, surface treating includes treating the sheath witha slurry including one or more of, alone or in combination, pumice,sand, glass, and/or mica.

In a further option, the method includes treating a portion of thesheath 112, such as a second portion 144 of the sheath 112 with a secondtreatment. In an option, the second treatment includes chemicallyetching the second portion 144. In yet another option, a portion of thesheath 112 is masked prior to the second treatment, such as the chemicaletching. For instance, the area at 145 can be masked prior to thechemical etching. In an option, the first portion 142 and the secondportion 144 overlap.

The method further optionally includes treating a portion of the sheath112 with a third treatment. For instance, the third treatment includesremoving at least a portion or all of the second treatment, such as thechemical etch. For instance, at least a portion 146 of the interface istreated with a third treatment to remove the second treatment such asthe chemical etch. In an option, the third treatment includesmechanically treating the portion 146, such as by buffing, blasting, orotherwise treating the portion 146. In still another option, the sheath112 is masked prior to the second treatment, such as the chemical etchto control where the chemical etch occurs.

It should be noted that the relative lengths and locations of the firstportion 142, the second portion 144, and the portion 146 can be varied,and the amount of overlap can be varied. For example, the amount ofoverlap can be varied to achieve a sufficient amount of attachmentbetween the handle assembly and the sheath 112, without interfering withthe ability of the sheath to be split and removed from around a devicetherein.

The method further optionally includes coupling a handle assembly withthe sheath at the surface treated interface. For instance, material isflowed over the sheath proxial end to connect the handle assembly to thehandle interface. In an option, the material is flowed through flowholes 119 (FIG. 3) of the handle interface.

Advantageously, the introducer assembly described above provides manybenefits. For example, the introducer assembly allows for a sheath, suchas a slippery sheath, to be effectively bonded with a handle assembly,and further provides a seal between the sheath and the handle. Forexample, a seal is provided when the sheath is chemically bonded withthe handle assembly. Furthermore, the methods and coupling techniquesincrease the tensile strength of the sheath to handle the bonding of thesheath and the handle assembly. In addition, the chemically etchedsheath can withstand higher temperatures, for example temperatures incertain manufacturing procedures, such as, but not limited to duringovermolding processes. The introducer assembly further allows forremoval of the introducer without disruption to the procedure orplacement of the medical device such as a lead.

It is to be understood that the above description is intended to beillustrative, and not restrictive. Many other embodiments will beapparent to those of skill in the art upon reading and understanding theabove description. It should be noted that embodiments or portionsthereof discussed in different portions of the description or referredto in different drawings can be combined to form additional embodimentsof the present invention. The scope of the invention should, therefore,be determined with reference to the appended claims, along with the fullscope of equivalents to which such claims are entitled.

1. A method for forming an introducer sheath, the method comprising:providing a lubricious polymer tube, the polymer tube forming a sheathextending from a sheath proximal end portion to a sheath distal endportion and having an intermediate portion therebetween, the sheathhaving a passage therethrough; surface treating the sheath proximal endportion and forming a handle interface; and coupling a handle assemblywith the sheath at the surface treated handle interface.
 2. The methodas recited in claim 1, wherein surface treating includes mechanicallyetching the handle interface.
 3. The method as recited in claim 2,wherein mechanically etching the handle interface includes blasting thehandle interface with sodium bicarbonate.
 4. The method as recited inclaim 1, wherein surface treating includes chemically etching theinterface.
 5. The method as recited in claim 4, wherein chemicallyetching includes etching with sodium naphthalene/ethylene glycoldimethyl ether solution.
 6. The method as recited in claim 1, whereincoupling the handle assembly with the sheath includes overmolding thehandle assembly on to the sheath.
 7. The method as recited in claim 6,wherein overmolding includes flowing material through holes of thesheath.
 8. The method as recited in claim 1, wherein surface treatingthe sheath includes mechanically etching the interface, and chemicallyetching the interface after mechanically etching the interface.
 9. Themethod as recited in claim 8, further comprising removing the chemicaletching.
 10. The method as recited in claim 9, wherein removing thechemical etching includes removing only a portion of the chemicaletching.
 11. The method as recited in claim 9, wherein removing thechemical etching includes mechanically removing the chemical etching.12. The method as recited in claim 8, further comprising masking aportion of the sheath proximal end portion prior to chemically etchingthe interface.
 13. The method as recited in claim 1, wherein surfacetreating the sheath includes treating the sheath with one or more ofsand, glass, mica, pumice, or dry ice.
 14. A method comprising:providing a lubricious polymer tube, the polymer tube forming a sheathextending from a sheath proximal end portion to a sheath distal endportion and having an intermediate portion therebetween, the sheathhaving a passage therethrough; surface treating a first portion of thesheath proximal end portion with a first treatment; surface treating asecond portion of the sheath proximal end with a second treatment andforming a handle interface; and coupling a handle assembly with thesheath at the surface treated handle interface.
 15. The method asrecited in claim 14, wherein surface treating the first portion with thefirst treatment includes mechanically treating the first portion. 16.The method as recited in claim 15, wherein mechanically treating thefirst portion includes mechanically etching the first portion.
 17. Themethod as recited in claim 14, wherein surface treating the secondportion with the second treatment includes chemically treating the firstportion.
 18. The method as recited in claim 14, further comprisingremoving the second treatment.
 19. The method as recited in claim 18,wherein removing the second treatment includes mechanically treating thesecond treatment.
 20. The method as recited in claim 14, furthercomprising treating with a third treatment.
 21. The method as recited inclaim 14, further comprising masking at least a portion of the proximalend portion prior to the second treatment.
 22. The method as recited inclaim 14, wherein treating with the first treatment includes blastingwith sodium bicarbonate.
 23. An introducer assembly comprising: a sheathextending from a sheath proximal end to a sheath distal end, the sheathhaving a passage therethrough; the sheath proximal end having a handleinterface, the handle interface having a first treated portion treatedwith a first treatment and a second treated portion treated with asecond treatment; and a handle assembly coupled with the sheath at thehandle interface.
 24. The introducer assembly as recited in claim 23,further comprising a dilator disposed through the passage.
 25. Theintroducer assembly as recited in claim 23, wherein the sheath is formedof PTFE (polytetrafluoroethylene).
 26. The introducer assembly asrecited in claim 23, wherein the first treatment is a mechanicaltreatment and the second treatment is a chemical treatment.
 27. Theintroducer assembly as recited in claim 23, wherein the handle interfaceincludes one or more flow holes therein.
 28. The introducer assembly asrecited in claim 23, wherein the first treated portion overlaps at leasta portion with the second treated portion.